1. Field of the Invention
The present invention relates to a hair-dyeing composition which comprises geraniintannin and a water-soluble iron salt and which has excellent black colorability, dyeability, color tone and color fastness, as well as to a hair-dyeing method using the same.
2. Prior Art
In general, a so-called gray-hair-dyeing composition for dyeing the gray hair of the aged is widely used. The gray-hair-dyeing composition which is generally used at present is essentially an oxidizing hair-dyeing composition. The hair-dyeing composition of this kind comprises a dye intermediate of an aromatic amino compound such as paraphenylenediamine, a coupler of a phenol compound such as m-phenylenediamine or m-aminophenol, and an oxidizing agent such as hydrogen peroxide or sodium perborate.
However, such a hair-dyeing composition has a drawback as a substance which is directly applied to the skin, as the dye intermediate component in the composition causes inflammation of the skin. In addition, the operation for dyeing hair with the composition is complicated since plural agents of the dye intermediate, coupler and oxidizing agent are to be used.
In order to overcome inflammation or any similar disorder of the skin by the said oxidizing hair-dyeing composition, a non-oxidizing type hair-dyeing composition has been proposed, which comprises a water-soluble iron salt and gallic acid, tannic aid and pyrogallol. (For example, refer to Japanese Patent Kokai Nos. 49-36838, 60-209513 and 51-56119.)
In addition, a hair-dyeing composition of another type is also known, which comprises Japanese gall, nutgall (Turkey gall) extract and ferric chloride (Japanese Patent Kokai No. 62-116504).
The non-oxidizing type hair-dyeing compositions by the prior art have defective problems in that the dyeability thereof is poor, the hair blackened therewith does not have a glossy and lustrous color tone which is intrinsic t black hair and the blackened hair is faded by shampoo and is lacking in color fastness.